Shearing attachment for sewing machines



June 6, 1950 H, s. KETCHAM ISHEARING ATTACHMENT FOR SEWING MACHINES Filed April 2, 1946 ORA/EX Patented June 6, 1950 UNITED STATES PATENT OFFICE SHEARING ATTACHMENT FOR SEWING MACHINES 2 Claims.

My present invention relates to a power driven shear for cutting cloth and the like, and more particularly to a cloth shearing device that" may be mounted upon and used as an attachment upon a sewing machine of the conventional household type.

An object of the invention is to provide a cloth shearing device of novel construction that may be used as an attachment upon a domestic type sewing machine.

Another object of the invention is to provide a power driven cloth shearing device which may be mounted in a simple and convenient manner upon the head of a sewing machine and driven by the needle bar thereof so that the hands of the operator will be free to guide a piece of cloth thereto.

Another object of the invention is to provide a shearing device for attachment to the operating head of a sewing machine that is adapted to be driven by the needle bar thereof with short and rapid strokes so that intricate patterns may be cut therewith.

A further object of the invention is to provide a cloth shearing blade assembly in which the cutting blades are of novel form and are maintained in shearing relation with each other in a new and novel manner.

Other objects and advantages of the invention will be in part evident to those skilled in the art and in part pointed out hereinafter in the following description taken in connection with an accompanying drawing, wherein there is shown by way of illustration and not of limitation a preferred embodiment thereof.

In the drawing:

Figure l is a front elevation partly in section showing my invention as applied to the operation head of a sewing machine,

Figure 2 is a side elevation of the device as shown in Figure 1 of the drawing,

Figure 3 is a plan view taken along line III-III of Figure 1, looking in direction of arrows,

Figure 4 is a sectional view taken along line IV-IV of Figure 1, looking in direction of arrows,

Figure 5 is a sectional view taken along line V-V of Figure 1, looking in direction of arrows, and

Figure 6 is a fragmentary sectional view taken along line VI-VI of Figure 1, looking in direction of arrows.

By now referring to the accompanying drawing it will be seen that the attachment contemplated by this invention provides a simple device by which a piece of cloth may be guided and cut.

either along a straight line or in an intricate pattern while the operator will have both hands free to guide the work. At the same time the shearing blades will be operated independently from the needle bar of a conventional sewing machine which may be driven by the usual foot treadle or by an electric motor as is now more commonly the case. In its preferred form the cloth shearing device or attachment as shown in Figures 1, 2 and 3 of the drawing comprise an outwardly extending bracket or blade supporting member Ill that is adapted to be secured upon a presser foot bar H of a sewing machine head l2 and which carries a conventional presser foot' l3. Adjacent to the presser foot bar I l, the sewing machine head 12 is also here shown as having a needle bar It that is adapted to reciprocate vertically as is well understood in the art. In this instance the needle bar I4 is shown as having a needle IS in its lower end, but during the operation of my device, as in the cutting of a piece of cloth, it is contemplated that the needle !5 will be removed from the needle bar I4. The bracket or blade supporting member In is here shown as preferably secured upon the presser foot bar II by a clamp [6 that is tightened by means of a thumb screw II, but it will be understood that this blade supporting bracket l0 may be secured upon the sewing machine in other manners that will be evident. At its extending end the blade supporting bracket in has a downwardly depending portion [8 that has spaced and slotted blade guiding flanges l9 and 20 between which a shearing blade 2| is mounted for vertical movement. At the upper edge of the shearing blade 2| there is a link 22 that connects with one end of a walking beam 23 which is pivotally mounted upon the blade supporting bracket III by means of a stud Z4 and extending to the other side of the stud 24 the walking beam 23 is provided with a forked end 25 that is adapted to straddle a stud 26 which projects from the side of the needle bar II. In this manner the shearing blade 2| is caused to move vertically in the blade supporting member ID and relative to a stationary blade forming member 21 as the needle bar l4 reciprocates when in operation. In this particular arrangement the stationary blade forming member 21 is in the form of a fiat plate having a rectangular slot 28 into which the lower end of the shearing blade 2| is adapted to project. This plate 21 is preferably mounted over an opening 29 formed in a table portion 30 of the sewing machine. At its cutting end the shearing blade 2| is shown as disposed at an angle and ground oil? on one side so as to provide an inclined shearing edge 3| that will cooperate with an adjacent sharpened side of the slot 28 in the stationary blade forming member 21. The shearing blade 2| also has a thickened portion or rib 32 along one side that serves, as will later appear, to position the bracket It] with respect to the axis of the presser foot bar I l and also maintain the cutting edge 3| of the shearing blade 2| in cooperating relation with the cutting edge formed along the side of the slot 28 of the plate 21.

By now referring to Figures 4, 5 and 6 of the drawing it will be noted that the slot 28 of the stationary blade forming member 21 is of greater width than the thickness of the vertically moveable shearing blade 2i. This is to provide for a shearing action along one edge of the slot 28. Therefore, as shown in these figures of the drawing the thickened portion or rib 32, referred to above as provided along. one side of the blade 2'i, operates to position the bracket l and main tain the moveable shearing blade 2i in shearing engagement with'the cutting edge of the slot 23 As a further means. in this direction the stationary blade forming member 21, as shown in Figure 4 of the drawing, is also provided with a blade biasing means in the form of a plunger 33' that is operated by a spring 34. In this instance the plunger 33: and the spring 34 are held in place by means of a screw plug 35. As shown in Figure 5 of the drawing, the moveable blade guiding slot in the flange IQ of the blade supporting bracket I0 is of a. width sufficient to accommodate the thickened portion or rib 32 while the slot in the flange 20 0f the bracket [0' is of av width corresponding to the thickness of the blade 21. In order to improve the shearing action between the sharpened edge 3| of the blade 2| and the engaged side of the slot 28 of the stationary blade forming. member 21 I may also form the cutting edge of the-slot 28 with a, slight upward projection as shown at 34 in Figure 6 of the drawing.

It is believed that the operation of my invention will be fully understood by those skilled in the art and while I have, for the sake of clearness and in order to disclose the invention so that the same can be readily understood, described and illustrated specific form and arrangement, it is to be understood that the invention isnot limited to the specific form and arrangement disclosed, but may be embodied in other forms that will suggest: themselves to persons skilled in the art. It is believed that this inventionis new and it is desired to claim it so that all such changes as come within the scope of the appended claims are to be considered as part of this invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a cloth shearing device of the character described, the combination of a flat vertically moveable blade having an angularly disposed cutting edge at its lower end, a stationary blade forming member having a slot therein wider than the thickness of said movable blade and sharpened along one side only into which said vertically movable blade is adapted to move, said first blade having a rib portion of uniform thickness extending vertically along its rear edge, and spring means carried by said stationary blade forming member adapted to continuously engage the rib portion of said moveable blade and maintain the angularly disposed cutting edge thereof in shearing relation with the sharpened edge of said stationary blade forming member.

2. In a cloth shearing attachment for sewing machines, the combination of a supporting bracket adapted and arranged to be secured upon the presser foot bar of a sewing machine, a shearing blade mounted upon said bracket for vertical reciprocating" movement, said shearing blade having a cutting edge formed at an angle along its lower end, a slotted plate carried by the table of the sewing machine having a guideway at one end of its slot and one side sharpened to form a stationary shearing blade with which the cutting edge of said first shearing blade is adapted to cooperate as it reciprocates, means forming a driving connection for'said' first shearing blade adapted to be operated by the needle bar of a sewing machine, and a blade guiding rib of uniformthickness' extending along the back of said reciprocating blade and slidably engaging the guideway in said slotted plate for maintaining the cutting edges of said shearing blades in shearing contact while they move relative to each other with a shearing action as the needle bar of the sewing machine reciprocates.

HELEN S. KEICHAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 224,219 Osborne Feb. 3, 1880 564,818 Batchelor July 28,v 1896 985,115 Kohn Feb. 21, 1911 1,946,558 Weis Feb. 13, 1934 

